Sudercharger for automotive vehicles



Jan. 20, 1948. s. M. UDALE A 2,434,726

SUPERCHARGER FOR AUTOMOTIVE VEHICLES Filed Nov. 17, 1945 Patented Jan.20, 1948 OFFICE SUPERCHARGER FOR AUTOMOTIVE VEHICLES Stanley M. dale,Detroit, Mich., assignor to v George M. Holley and Earl HolleyApplication November 17, 1943, Serial No. 510,842

The object of this invention is to apply a supercharger to an internalcombustion engine mounted on an automotive vehicle. The problem is todevise a supercharger that is suclently cheap so that the automotiveindustry can afford to buy it as an engine accessory. Such an accessoryshould not raise the power too much at sea levelotherwise the enginewill burn up and--for example, at Denver it should enable the engine todevelop maximum horsepower.

Heretofore, superchargers have been tried out and have always been foundto be too expensive or they caused the engine to wear out too rapidlyand the result has been that to date superchargers have not come intogeneral use. In fact, they are hardly used at all in the automotivefield.

The drawing shows diagrammatically the preferred form of my invention.

II) is the air entrance. blower. I2 is the inlet air cleaner andsilencer. I3 is the choke valve. I4 is the plain tube carburetor ingeneral use. I5 is the throttle valve. I6 is the inlet manifold. I'Iis'the hot spot. I8 is the thermostatically controlledexhaust valvecontrolled by a thermostat I9. This valve is designed so that the flowof exhaust gas blows it into the open position. is the exhaust manifoldfrom which the stream of exhaust gases flows against the valve I8. 2| isthe exhaust outlet to a muffler (not shown).

When the exhaust controlled valve I8 moves to the position shown inbroken lines, there is a bypass 22 which provides an alternative outletfor the exhaust gases. When the exhaust gases flow along this bypass 22they strike the lmpeller of the turbine 23 which drives the blower IIand supercharges the engine.

A throttle valve 24 is connected to the valve I5 so that whenever thethrottle I5 is shut the valve 24 is open so that whether the engine ishot or cold the exhaust gases alway: escape through the exhaust outlet2l when the turbine 23 is not operating.

A valve 25 operated by the diaphragm 26,

` which is subjected to the depression in the inlet manifold I6,controls a fuel passage 2l which provides additional fuel when thethrottle I5 is wide open. The spring 28 is not strong enough to keep thevalve 25 open whenever the throttle I5 moves out of the wide openposition. The addition of this vacuum operated valve is no part of thisinvention and such devices have been in use for the last ten years.

The spiral thermostatic element I9 may be re- II is an impeller or 7Claims. (Cl. 60-13) placed .by a spiral steel spring I9 made ofnonthermostatic material, in which case the valve I3 will be opened onlyby the flow of exhaust gases impinging on the right leg which is longerthan the left leg, the valve I8 being eccentrically mounted in theexhaust manifold.

In automotive practice, it is customary to mount a fan 29 driven by apulley 30 and a belt 3|, which belt is driven by the engine. This ianblows air over the exhaust manifold and also over the thermostat I9which is arranged to be in the path of the air blown by the fan 29. Asthe water in the radiator takes some time to become warm there is adefinite period of time before the fan blows warm air over thethermostat I9. 'I'he thermostat I9 is located adjacent to the wall ofthe exhaust manifold outlet. The thermostat is thus subjected to thetemperature of the air drawn through the radiator and also to the heatradiated by the exhaust manifold.

A diaphragm pump 32 operated by an engine driven eccentric 33 pumps fuelfrom a tank 34 through an inlet pipe 35 and an outlet pipe 36 to thefloat chamber 31. Check valves 38 and 39 perform the usual functions ofcheck valves in a fuel pump. The pump diaphragm 32 is operated by acompression spring 4t! in a well known manner. A pipe 4I connects theair entrance 42 located above the venturi I4 with a chamber 43 locatedabove the diaphragm 32. The passage 44 connects the upper part of thefloat chamber 31 with the air entrance to the carburetor on theatmospheric side of the choke I3.

Operation When the throttle is in the position shown and the engine hasjust been started, the exhaust valve 24 and the temperature responsivevalve I8 are also in the positions in which they are shown. When thethrottle I5 is open the temperature responsive valve I8 remainsl in theposition shown if the weather is very cold. In such weather thethermostat I9 holds the temperature-responsive valve I8 in the positionshown. However, when the engine warms up the ther-. mostat I9 permitsthe valve I8 to open under the influence of the exhaust gases flowingout of the exhaust manifold 20. When this happens, exhaust gases impingeon the turbine 23 and thc blower II rotates and supercharges the air tothe engine.. When the throttle I5 is closed, the valve 24 opens and thesupercharger quits.

When an engine is started cold, the lubrication is imperfect and duringthe warming up period the oil circulates and the walls of the cylindersbecome lubricated. The eneet of a supercharger is to increase the powerof an engine. Therefore, the tendency oi an engine to seize or burn outincreases with the power. With the thermostat it operating, the valve isis held in the position shown despite the fact that the throttle i isopen and the valve 24 is closed.

Therefore, under such conditions and until the engine warms up, theexhaust gases escape through li without rotating the turbine 23. Henceit is impossible to get extra power from this supercharger setup untilthe engine has been run an appreciable number of minutes and the oil isfree to circulate, after which time it is safe to impose upon the enginethe added load due to the supercharger of the engine.

When operating at Denver it will be desirable to place the valve 2d inthe closed position at all times, that is, in the position shown by thebroken lines. rThe reason for this is that when operating at Denver itis desirable to have the supercharger operating all the time except, ofcourse,

during the warming up period. The reason why it is desirable to run thesupercharger all the time at Denver is that otherwise the mixture ratiobecomes rich at part throttle and, of course, it is at part throttlethat the mixture ratio determines mileage. f

The carburetors are designed forsea level and when they get to 'Denverthe mixture becomes too rich for good mileage. When operating at sealevel, however, if the supercharger runs all the time the mixture ratiowould become too lean at' part throttle for the same reason. The mixtureration at wide open throttle ig alwaysfon the rich side.

in order to provide the extra fuel that is needed at wide open throttlewith the supercharger operating at its maximum capacity, the restricted:fuel passage 2l would be changed so that the only departure fromstandard production necessitated by the addition of a supercharger is toenlarge the fuel passage @l to permit a greater amount of fuel to betaken into the engine at wide open throttle to provide fuel for the airadded by the supercharger. The compression ratie would be unchanged, forthe reason given. in operating a supercharged engine, it is verynecessary to be sure that at maximum power the mixture ratio issufficiently rich t prevent the exhaust valves burning. Obviously, iimaximum power is accompanied by a lean mixture, the engine will, be inthe garage being serviced so much of? the time that the idea of using asuper-charger will be discredited. It is therefore extremely importantthat the flow of fuel through the passage 2li be suiiciently great tomaintain, when the throttle is wide open and the supercharger is inoperation, a sufficiently rich mixture so that the engine exhaustvalves, etc., will not burn out.

The element lil has two functions.

(a) it acts as a thermostat to delay the operation ci' the superchargeruntil the engine has warmed up.

(o) After the engine has warmed up, it acts as spring load on the valvei@ to permit exhaust gases to open the valve and to close the valve andto reiease the exhaust into the bypass 2i whenever the engine runsslowly or idles, when the exhaust gases are no longer powerful enough toopen the valve.

The time interval is determined by the act that the thermostat illresponds partly to the exhaust temperature, partly to the temperature ofthe exhaust passing through the outlet 2li, partly the hood, whichtemperature is largely controlled by the temperature of the air drawnthrough the radiator by the fan 28, which temperature is determined bythe time the engine has been running, the speed and load under which theengine has been running, and the atmospheric temperature.

When the engine is in operation, a pressure is created in the floatchamber 31 through the passage which pressure is equal to thesupercharger pressure. This pressure` is transmitted through the pipe 4lto the chamber 43 so that the pressure acting on the diaphragm 32 is thesum of the spring 40 plus the pressure in the air entrance l2. Hence,when the supercharger is operating the pressure of the fuel in theoutlet pipe 3B increases so that the fuel will iiow into the floatchamber 31 under all conditions.

What I claim is:

1. The combination with an internal combustion engine having an airentrance, a carburetor. a throttle valve therefor, an inlet manifold, ahot spot therefor, an exhaust manifold in heat conducting relationshipwith said hot spot, an exhaust valve located in said exhaust manifoldand adapted to direct the flow of exhaustv gases against and away fromsaid hot spot, a. relatively free outlet from said hot spot, a secondoutlet means responsive to the flow of exhaust gases inside said exhaustmanifold adapted to move said exhaust valve so as to divert the flow ofrexhaust gases away from said hot spot and said outlet to a secondoutlet for .said exhaust gases, a turbof supercharger adapted to beoperated by said exhaust gases owlng through said second outlet, saidturbo-supercharger being connected to the air inlet to said engine andadapted to supply air under pressure thereto.

2. A device as set forth in claim 1 in which a mechanically operatedexhaust valve is located in said iirst exhaust outlet and in series with'and on the downstream side of said exhaust operated valve, meansinterconnecting said mechanically operated exhaust valve with saidcarburetor throttle valve whereby these two valves are operatedsimultaneously and the mechanically operated exhaust valve is movedtowards its open position whenever the carburetor throttle is movedtowardsits closed position so as to permit the exhaust gases to escapethrough said ilrst outlet.

3. A device as set forth in claim 1 in which there is a temperatureresponsive means located outside of and adjacent to said exhaustmanifold and in which the exhaust valve is also controlled by saidtemperature responsive means.

4. The combination with an internal combustion engine having an airentrance, a carburetor, a throttle valve therefor, an inlet manifold, ahot spot therefor, an exhaust manifold in heat conducting relationshipwith said hot spot, an exhaust valve located in said exhaust manifoldand adapted to direct the flow of exhaust gases against and away fromsaid hot spot, a relatively free outlet from said hot spot, a secondexhaust outlet, temperature responsive means located outside of andadjacent to said exhaust manifold and adapted to control said exhaustvalve so as to divert the iiow of exhaust gases from said outlet to saidsecond outlet for said exhaust gases, a turbo-supercharger adapted to beoperated by said exhaust gases flowing through said second outlet, saidsupercharger being connected to the air inlet to said engine.

5. A device as set forth in claim 4 in which a mechanically operatedexhaust valve is located in said first exhaust outlet and in series withand onvthe downstream side of said exhaust operated valve, meansinterconnecting said mechanically operated exhaust valve with saidcarburetor throttle valve whereby these two valves are operatedsimultaneously and the mechanically operated exhaust valve is movedtowards its open position whenever the carburetor throttle is movedtowards its closed position so as to permit the exhaust gases to escapethrough said rst outlet.

6. In combination with an internal combustion engine having aturbo-supercharger, a carburetor and an exhaust manifold connected tosaid supercharger, an exhaust outlet from said manifold which permitsthe exhaust gases to bypass said turbo-supercharger, a spring loadedeccentrically mounted valve responsive to exhaust ow located in saidexhaust manifold and adapted at low ex- 6 haust ow to divert the ilow ofexhaust gases into said bypass and at high exhaust ow to direct the flowof exhaust gases into said turbine so as to drive saidturbo-supercharger and to supercharge the engine.

7. A device as set forth in claim 6 in which there are means for heatingthe incoming air adapted to be heated by the exhaust gases diverted intosaid bypass.

STANLEY M. UDALE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,881,860 Muzzy Oct. 11, 19322,297,235 Mller Sept.I 29, 1942

